Effective Matter Cosmologies of Massive Gravity: Physical Fluids

TL;DR

This paper derives new cosmological solutions in ghost-free massive gravity where the mass sector acts as an effective cosmological constant and an ideal fluid obeying thermodynamics, ensuring energy conservation.

Contribution

It introduces a novel class of cosmological solutions with a general background metric incorporating an effective cosmological constant and thermodynamically consistent ideal fluid in massive gravity.

Findings

New solutions with effective cosmological constant and ideal fluid

Fluid obeys thermodynamics and energy conservation

Applicable to general background metrics

Abstract

We derive new cosmological solutions of the ghost-free massive gravity with a general background metric in which the contribution of the mass sector to the metric one is modeled by an effective cosmological constant and an ideal fluid which obeys the first law of thermodynamics; thus it satisfies the ordinary energy-momentum conservation or continuity equation.